000 AXPZ20 KNHC 290333 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 0405 UTC Wed Nov 29 2017 Tropical Weather Discussion for the eastern Pacific Ocean from the Equator to 32N, east of 140W. The following information is based on satellite imagery, weather observations, radar, and meteorological analysis. Based on 0000 UTC surface analysis and satellite imagery through 0200 UTC. ...SPECIAL FEATURES... Gulf of Tehuantepec Gale Warning: The pressure gradient across southern Mexico continues to slowly weaken this evening, as high pressure has weakened across the Gulf of Mexico. Gale force winds ended this morning across the Tehuantepec region, and have diminished to 20-25 kt this evening, with seas 6-7 ft. Nocturnal drainage effects are expected to increase winds to near 30 kt by sunrise Wednesday morning. Winds are then expected to increase very slowly during the day Wednesday, and reach gale force before sunset, as moderate northerly wind flow become established across the western Gulf of Mexico. Northerly winds of 30-40 kt are expected across Tehuantepec Wednesday night through Thursday morning before diminishing to minimal gales throughout the day. Gale force winds to 40 kt are expected again Thursday night, with minimal gales expected to linger Friday morning through Saturday. During this extended gale event, seas are forecast to peak at 12-14 ft early Thursday morning, with downstream seas of 8 ft and higher reaching as far as 10N 100W Thursday night. INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough axis extends from 09.5N75W to 10N80W to 06N100W to 06.5N107W, where it transitions to the ITCZ and continues on to 09.5N128W to beyond 10N140W. Widely scattered moderate isolated strong convection is from 06.5N TO 10N between 79W and 85.5W, and from 07N to 11.5N between 94W AND 97.5W. Scattered moderate to strong convection is noted from 09N to 12.5N W of 139W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... See Special Features paragraph above for information on the Gulf of Tehuantepec Gale Warning. The tail end of a stalled cold front across the far N portion of the Gulf of California and highlands of Sonora has dissipated across the area this evening. NWly winds area assumed to have diminished to 15-20 kt N of the Tiburon Basin, where seas have subsided to 3-5 ft. High pressure centered over the Pacific waters W of Southern California extends a ridge SE into the area to near 18N110W, and is producing moderate to fresh NW winds across the Pacific waters of Baja California. NW swell moving through the waters is leading to combined seas of 8 to 12 ft across the waters N of Punta Eugenia, and 5 to 9 ft southward to the waters off of Cabo San Lucas. This swell will continue to propagate SE, with seas 8 ft and higher reaching the Revillagigedo Islands by late Wed afternoon. Seas across the waters W of Baja California to the Revillagigedo Islands will remain above 8 ft through late this week, as another reinforcing pulse of NW swell propagates into these waters Wed through Fri. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Gulf of Papagayo: A modest pressure gradient between high pressure over the western Gulf of Mexico and lower pressure across the southwest Caribbean is producing fresh to strong offshore gap winds across the Papagayo region, and will enhance overnight drainage effects. This will result in pulses of fresh to strong gap winds across the Gulf of Papagayo for the next few days, maximizing during the late night through morning hours. Seas downstream will build to 6 to 8 ft during the early morning hours, with winds and seas diminishing slightly each late afternoon through evening. Light to gentle N to NE winds, and 4 to 5 ft seas are expected elsewhere through Sat N of the monsoon trough. Moderate southerly winds, and 4 to 6 ft seas, are forecast south of the monsoon trough. Northerly swell generated in the Gulf of Tehuantepec has reached the western part of forecast zone PMZ111 (offshore waters of Guatemala and El Salvador) where seas of 7 to 8 ft this evening will diminish through early tonight. Additional moderate to large mixed NW and N swell will reach the western portion of zone by Thu through the end of the week. REMAINDER OF THE AREA... A large area of NW swell producing seas of 8 to 14 ft will continue to propagate across the region with the leading edge of 8 ft seas currently reaching from the central Baja California peninsula to 08N140W this evening, and will reach from 28N115W to 20N120W to 05N140W Wed, and from 28N115W to 16N110W to 00N140W Thu. A re-enforcing pulse of NW swell will reach the NW waters late Wed through Thu, as seas of 8 to 12 ft cover nearly the entire forecast waters S of 30N W of 110W Fri through the upcoming weekend. $$ Stripling